TV Remote for Magnavox TV

I have a Magnavox RS1960 W101 TV. The remote works fine to turn the TV on and off and to enter menu selections and to channels. I cannot use the up and down volume or channel arrows, mute, or A/CH (previous channel) buttons. Any thoughts??? The remote had not been used for a long time as I had another that I used via a VCR. I changed the batteries in it, also. Thanks so much.